Great Lakes Avian Radar Technical Report Lake Niagara, Genesee, Wayne and Jefferson Counties, New York

Global wind patterns assist the migration of millions of birds and bats through the Great Lakes region, where shorelines provide important stopover habitat. Shorelines are thought to concentrate migrants because they offer the last refuge adjacent to a geographic obstacle and are likely used for navigation. Shorelines are also attractive for wind energy development. Because of this potential for conflict of interest, more information is needed on the aeroecology of the Great Lakes shorelines. We used two avian radar systems to simultaneously identify the activity patterns, timing, and duration of migration along the shorelines of the Great Lakes. We placed avian radar systems near Lake Ontario in New York, where the automated systems continuously tracked and recorded target (bird and bat) movements from late March to early June, 2013. We calculated the direction of movement, target passage rates, and altitude profiles for the air space above our study areas. We also modeled the vertical sample volume to estimate target density by altitude band.